In a typical high-power Vertical Cavity Surface Emitting Laser (VCSEL)-array assembly, several light emitting semiconductor devices as, for example, submounts comprising a certain number of VCSEL-array chips will be mounted together on mounting areas of the same cooling structure as, for example, a μ-channel cooler. As preparation for the assembly- or mounting process, trenches are cut into the top surface of these μ-channel coolers to create a (typically rectangular) structure of mounting areas as shown in FIG. 4. This usually is done in a separate laser-structuring step, after manufacturing of the μ-channel coolers. The structure in the top surface mainly serves as a solder-stop; in this way, a defined positioning of the submounts on the cooler-surface is achieved. This in turn helps avoiding electrical contacts and shorts between the submounts and allows a better definition of the laser-radiation-emitting area from the cooler. Another purpose of the trenches in the cooler surface is to provide for a reservoir for excess solder during the soldering of the submounts.
The described method of manufacturing the mounting areas and consequently the cooling structure is time-consuming, costly and may introduce additional tolerances with respect to the positioning of the submounts which may be inacceptable for applications requiring precise control of the positioning.